Wireless help

by **Camel toe joe** » Mon Sep 06, 2004 3:14 pm

I just bought a DI624 D-link wirless router and dwl-925 card for my laptop. so far it's not been working too well. on of the main problems i believe is that the houses here in PR are made of concrete with steel rebar so i'm not sure if that is the problem or is it the hardware??? this is my first time using wireless :roll:

know ofany programs that tell me about signal strength?? also i don't think it's getting intereference since my wireless phone is 900 mhz and the rputher uses 2.5ghz any help would be appreciated 8O

by **Chacal** » Tue Sep 07, 2004 2:08 am

What happens if the computer is in the same room as the router?

by **red_mist** » Tue Sep 07, 2004 4:49 am

Then there would be no need for wireless would there.

by **Chacal** » Tue Sep 07, 2004 7:47 am

by **Tommy Boy** » Tue Sep 07, 2004 9:42 am

I just did a similar install for my in-laws and was having some real troubles with the range too...I was using a Linksys wireless router and literally had to have it within 25 feet of the computers in order for it to get any signal.

I would welcome any help too!

by **SHWoff** » Tue Sep 07, 2004 10:17 am

Well... Any material will affect the propagation of the wireless signal - some more than others. Unfortunately for Camel, the rebar and concrete walls would be some of the worst. The typical 802.11a, b, or g device transmits at a maximum of 100mW, which is far less than many other wireless devices such as cellular phones or walkie talkies. This means that any degradation of signal is potentially disastrous. If my mind serves me (it does on and off...), the typical 802.11b/g device should be able to transmit through 1-1/2 walls of typical (American) indoor construction - that is, 2x4s spaced at 16-inches and 1/2-inch drywall - and still maintain a decent connection. Any more than that and the coverage will be spotty... You can place the AP in hallways or in a central (large) area with open doors to maximize the coverage.

Other things to consider are old microwaves that may have some leakage (it's scary that microwaves operate at the same frequency as 802.11b/g yet at much higher power... - huh?), 2.4GHz phones, 2.4GHZ baby monitors, etc. These may interfere with the wireless signal.

As far as wireless tool to measure the signal strength/quality, I'm used to enterprise tools such as AirMagnet and Berkeley Varitronics YellowJacket. So, not much use on the home front. The Cisco card and client (ACU) has a pretty good signal detector but you have to be associated with an AP to use it. I'm not sure if D-Link has added anything in their client (mine doesn't have it).

I'll check with some of the guys at work and see if there's anything free out there that you can download...stay tuned....

BTW. I'd do as Chacal recommended and try it in the same room to baseline then slowly move outward to determine coverage....

by **deathBOB** » Tue Sep 07, 2004 11:05 am

Originally posted by SHWoff
(it's scary that microwaves operate at the same frequency as 802.11b/g yet at much higher power... - huh?)

So if i set my router to high, how long would it take to pop my popcorn?

by **SHWoff** » Tue Sep 07, 2004 1:18 pm

Originally posted by deathBOB
So if i set my router to high, how long would it take to pop my popcorn?

Well...luckily, 100mW is much less than the 1200W microwave, but it still makes makes you wonder. The microwave works by causing rapid movement in water molecules causing friction. The friction heats up the water which heats up the product.

Here's some interesting facts... there is something called acceptable loss - which is the radio waves that "leak" from the microwave. Also, microwave makers usually only guarantee the acceptable loss for ~5-years.

Bet you'll think next time you look through the little window in front to see if the food is hot or the water is boiling.....

by **Camel toe joe** » Tue Sep 07, 2004 2:19 pm

well in the room it works fine, I found a little program that seems to be pretty nice it's called netstumbler, http://www.netstumbler.com/ gives a bunch of info about the wireless networks in your range. anyway I'm gonna borrrow my friends wirless router and see if i get a better signal. I figured the walls would be a problem. and I really don't want to spend much money on APs so I settle with limited rage i guess

by **SHWoff** » Tue Sep 07, 2004 3:22 pm

Netstumbler is a great program. Kismet is another good one. Apparently, Knoppix (Linux) comes with Kismet and a number of good wireless tools....

So, they actually use concrete and rebar for the inside walls too? Is there a more central location that you can locate the AP?

by **Camel toe joe** » Tue Sep 07, 2004 5:16 pm

Originally posted by SHWoff
So, they actually use concrete and rebar for the inside walls too? Is there a more central location that you can locate the AP?

actually the internal walls of the house are just cinder blocks no rebar...and I might try diffrent rooms but i prefer keeping it in the same room as my wired PC because I have the battery back up there and power outages and surges are common in my area..

by **Chacal** » Tue Sep 07, 2004 9:16 pm

You could put a 2nd AP in the second room where it has a direct line-of-sight with the first and daisy-link them.

Double the cost though.

Oh and are the 2 rooms on the same floor? The underside of the AP is usually shielded.

by **Camel toe joe** » Wed Sep 08, 2004 11:49 am

Originally posted by Chacal
You could put a 2nd AP in the second room where it has a direct line-of-sight with the first and daisy-link them.

Double the cost though.

Oh and are the 2 rooms on the same floor? The underside of the AP is usually shielded.

different floors I'm thinking of buying or building an antenna

by **SHWoff** » Wed Sep 08, 2004 12:28 pm

Originally posted by Camel toe joe
different floors I'm thinking of buying or building an antenna

Well... For coverage, the omnidirectional (dipole) antenna that usually comes with the AP/router provides the best coverage. It provides an almost circular horizontal pattern and about 180 degrees above and below.

A patch antenna would provide a little gain in a directional mode with probably around 180 degrees horizontal and around 120 degrees vertical.

A yagi would provide a little more gain with a minimal coverage pattern much like a flashlight.

So... Unless you are targeting a specific area, I'm not sure if an antenna will solve your issues (although, there's always the possibility that it might...). You also have to remember that the client cards usually come with omni antennas so whatever you do on the AP/router side, you'll have to duplicate at the client...

Some good antenna info can be found here

Check out the radiation patterns here

Finally, I get a lot of my current WLAN info at Wi-Fi Planet. Here is a link to a good brief article on maximizing coverage with antennas....

Wireless help

Wireless help

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